JoelSim said:
The key is in the phrase 'if you rip at high quality'. Standard 128kbps bitrate MP3 is hugely worse than CD.
I suppose there's a reason these things come up, but I'm not going to guess why. Suffice it to say that the mantra of "you can't hear blah blah blah" just isn't true. 320k CBR MP3's converted from perfect CD WAV rips don't sound as good. Now you can set up a demonstration with 15 people in a room and give each one the best headphones and have at it, and you won't come to a conclusion for several reasons: 1) The background noise level won't be as quiet as at home late at night (or in a soundproofed home). 2) The noise inside of most of the people from the energy being generated to pay attention and participate is very significant. 3) Subliminals (very significant in hi-fi) just don't register in active attention tests. 4) Untrained listeners miss things that others recognize.
Those are just a few examples. 320k CBR MP3's have a lot of information removed**, and I know people who can hear the differences easily. It helps to have a good revealing system to hear those differences, but to say that nobody can hear them because the tests are fatally flawed from the start isn't a good argument.
**The compression is approx. 4.4 to 1, or a 77 percent loss.